<!DOCTYPE html>
<html lang="zh">
	<head>
		<meta charset="utf-8">
		<link rel="stylesheet" href="style.css">
		<title>05 按钮文字上下滑动</title>
	</head>
	<body>
		<div class="app">
			<button>
				<span class="defalut">鼠标放上来</span>
				<span class="hover">点我吧</span>
			</button>
		</div>
	</body>
</html>